1. Technical Field
An embodiment of this invention relates to the field of portable batteries, and more specifically, to a portable battery for use with a single adapter/charger and a set of electronic devices having differing power requirements.
2. Description of the Related Arts
Supplying continuous DC power when away from an AC power source for more than a few hours often becomes a problem for a portable electronic device such as a laptop computer or a personal digital assistant (PDA). Such portable devices typically have a built-in space to receive a rechargeable battery pack as a primary power source when the device is in portable use. The rechargeable battery pack typically lasts only a few hours. Once the rechargeable battery pack is exhausted, the electronic device has to be turned off. In order to continue its operation, a user can bring along a back-up battery pack, which is identical in shape and design with the pack installed in the battery pack. Once the first installed battery pack is discharged to a low level after few hours of operation, the backup battery pack can be installed to replace the first installed battery pack for continuous operation. However, before the battery replacement, the device often must be powered down properly. In the case of a laptop computer, before it is turned off, the files which the computer is executing must be properly closed and some files often must be saved in order to preserve the works performed on the computer, which may be lost either due to the total exhaustion of power supply or its improper powering down. The powering down process typically generates interference and interruption to a user that is not only annoying but also decreases the user's effectiveness and productivity.
Operation with a portable electronic device and a conventional AC/DC adapter has another difficulty. There is a restriction that the installed battery pack is generally not charged when the electronic device is in operation due to the fact that the input current is mostly used for supporting the operation of the electronic device. Thus, in order to charge a battery pack, the device usually has to be turned off. In the case of a slow charging, either by a built-in charging circuit or the adapter, in order to fully charge the battery, the electronic device has to be temporarily out of service in the charging period. Again, the limitation of not able to efficiently and rapidly charge the battery pack reduces the usefulness and productivity of the portable electronic device.
There are backup batteries in the art that are used to supply power to electronic devices. One such backup battery system includes an adapter, an input interface, a charging circuit, the backup battery, and an output interface that is directly coupled to the electronic device being powered. However, such a system is deficient because the original adapter of the electronic device must be used while the backup battery is being powered. As disclosed in the prior art, the original adapter of the electronic device is utilized while: (a) supplying DC power to the electronic device, and (b) powering the portable backup battery. The prior art discloses a universal adapter interface that hooks up to the original adapter of the electronic device.
However, it is inefficient to have to utilize the original adapter of the electronic device being powered. For example, if a user is powering the backup battery while it is hooked up to a portable laptop computer, the user must utilize the original adapter of the portable laptop computer. If the user then decides to power a cellular phone, or other electronic device, the user must remove the adapter for the portable laptop computer, and replace it with the adapter for the cellular phone so that (a) the cellular phone, and (b) the backup battery, can be simultaneously powered.
Accordingly, systems in the prior art are deficient because a user must change adapters when the user decides to power different electronic devices while the backup battery charges. Also, due to the bulkiness of the adapters, it is awkward for a user to have to since multiple adapters to power different electronic devices.